Portion of a flat hair iron



FIG. 1 is a perspective view of a portion of a flat hair iron according to the present invention shown mounted on a flat hair iron;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a front elevation view thereof; and,

FIG. 6 is a right side elevation view thereof.

The broken lines shown in the drawings are for the purpose of illustrating environmental structure and form no part of the claimed design. 

The ornamental design for a portion of a flat hair iron, as shown and described. 